Gram quantities of known, representative siderochromes (microbial iron transport compounds) will be prepared. The catalogue of siderochromes will be expanded by investigation of new microbial genera. The stability constants for binding ferric, ferrous and other bio-metallic cations will be measured. The ability of the deferri-siderochromes to remove iron from ferritin, iron transferrin and hemosiderin will be examined both in vitro and in experimental animals. This research is designed to uncover an iron chelating agent which will be effective for treatment of the chronic iron overload which is a consequence of both iron storage disease and the therapy used for Cooley's anemia (thalassemia).